This invention relates generally to toothed power transmission belts, more particularly to the use of bias woven two-component nonstretch fabric for the tooth covering for toothed belts, and specifically to a bias-oriented woven fabric for a tooth cover fabric wherein the warp and weft are blended aramid/nylon yarns, and the weave is a modified plain weave.
Toothed belts are used widely in automotive engine timing drives, and in various industrial power transmission applications. Toothed belts generally include an elastomeric body with a series of protruding teeth which mesh with matching grooved pulleys or sprockets. A tensile member is embedded in the belt body to restrict stretching and maintain tooth pitch. A tooth cover or jacket is provided to strengthen the teeth and provide abrasion resistance. The jacket is usually based on a cover fabric coated with one or more treatments such as adhesive dips, calendered coatings, and laminated layers.
U.S. Pat. No. 4,343,666 discloses a toothed belt with a tooth jacket made from a piece of fabric, which is wrapped circumferentially around the cylindrical mold body to form the jacket of the individual belts. The fabric may be square woven, biased, stress-relieved or stretchable. Preferably, the elongation of the fabric should be at least 60% to insure that the fabric will completely conform to the shape of the grooves, without undue strain or rupture.
U.S. Pat. No. 2,519,590 discloses bias-cut-fabric covered power transmission belts wherein warp and weft threads are disposed between 90 and 180° included angle and disposed between 47.5 and 75° with respect to the longitudinal axis of the belt. Belts such as V-belts are described wherein the entire rubber core of the belt is covered with fabric.
U.S. Pat. Nos. 4,632,665 and 4,514,179 disclose tooth covering that is preferably a balanced cloth fabric consisting of nontextured warp and weft yarns preferably bias-cut so that the warp and weft yarns each make an angle of between 30 and 60 degrees with respect to the longitudinal axis of the belt. Each yarn is made up of many filaments. In a preferred embodiment of the invention the cover consists of a wear-resistant fabric in which the warp and weft yarns are nylon and which is a “non-stretch” fabric. Also disclosed is a preforming method for making toothed belts.
U.S. Pat. No. 6,595,883 discloses a V-belt suitable for clutching applications with a textile component employing any suitable or conventional type of textile material including weaves of warp and weft threads at any desirable angle of any natural or synthetic variety. In a preferred embodiment the fabric is a nylon/cotton blend bias-fabric weave with warp at an angle of 100 to 130° to the weft, and both oriented in a direction of about 57°±7° to the direction of travel or longitudinal direction of the belt.
U.S. Pat. No. 7,909,720 discloses a tooth cover may be of any desired configuration, including conventional weave with warp and weft and including cut on a bias, and using any of a laundry list of materials. The cloth canvas layers may be cloth made by plain weaving, twill weaving, satin weaving, or the like, using threads formed from cotton, polyamide fiber, polyethylene terephthalate fiber, or aramid fiber. The preferred embodiment utilizes nylon-66 woven stretch fabric. The only embodiment in the examples uses a single ply cotton canvas layer treated with an RFL solution.
U.S. Pat. Publ. No. 2009/0227406 A1 discloses a tooth cover may be of any desired configuration, including conventional weave with warp and weft and including cut on a bias, and using any of a laundry list of materials. The preferred embodiment disclosed, and the only embodiment in the examples, utilizes tooth fabric of nylon-66 woven fabric laminated with polyethylene film on the external tooth surface.
U.S. Pat. No. 3,784,427 discloses a method of making and treating bias cut fabric suitable for V-belt covers and hose reinforcing.
U.S. Pat. No. 3,832,210 discloses a method of preparing bias cut fabric related to helically cutting strips of bias fabric from a length of tubular fabric.
U.S. Pat. No. 4,238,530 discloses a method for producing continuous, spliceless bias fabric wherein warp and weft threads are disposed between 90 and 150° included angle.
U.S. Pat. No. 4,907,323 discloses a slitting method and apparatus for making bias fabric.
U.S. Pat. No. 5,255,419 discloses tentering apparatus and a related method.
U.S. Pat. No. 6,494,235 discloses a method and weaving machine for continuously making bias-bound fabric applicable to engineering fabrics based on flat yarns.
U.S. Pat. Publ. No. 2010/0275764 discloses a woven fabric from yarns used in the manufacture of ballistic projectile or puncture resistant articles.
U.S. Pat. Nos. 6,605,014 and 4,343,666 also disclose methods of making toothed power transmission belts including various tooth preform methods.
It is not known or suggested to use a bias-oriented woven fabric for a belt tooth cover fabric wherein the warp and weft are blended aramid/nylon yarns and the weave is a modified plain weave or a modified twill weave or a modified satin weave.